DYNAMICS OF THE YIELD OF WINTER WHEAT WITHIN THE BOUNDARIES OF THE VOLYN OBLAST

The problem of the lack of a perfect informational, regulatory and organizational-functional system that would regulate and ensure the scientifically based use of land in the conditions of agricultural reform, restructuring of land ownership, and the emergence of many new land users and landowners, increasing competition for land resources due to urbanization transport, other non-agricultural use is an urgent problem in Ukraine. It was investigated that the yield level of winter wheat within the Volyn region fluctuates almost one and a half times, which is caused by the heterogeneity of the soil and climatic conditions of the region. The general yield levels of winter wheat were established: it is the largest for cluster 1 (Forest-steppe zone), the smallest - for cluster 2 (Polyssia) and has an intermediate value for cluster 2 (transition zone). The approach of the specific yield of cluster 3 to the zero level emphasizes the stable transitional nature of the corresponding space within the Volyn region. After 2000, the rate of yield growth within Polissia began to rapidly decrease compared to the rate of growth of winter wheat yield in the Forest Steppe, so the share in the total yield in the region became smaller in Polissia. Variability in time of winter wheat yield is the smallest in the south and center of the region, and the largest in the north, east and west. The presence of asymmetry indicates the heterogeneity of winter wheat yield conditions and regimes during the research period and the possibility of establishing qualitatively homogeneous time intervals, i.e., the periodization of the studied time according to winter wheat yield indicators. The asymmetry of the distribution is also accompanied by its two peaks (there is a strong positive correlation between asymmetry and kurtosis r = 0.95, p < 0.001). Such results emphasize the presence of heterogeneous periods in the temporal yield of winter wheat during the research period. Periodization by types of winter wheat yield dynamics established that in periods 1 and 2 it was synchronous in all spatial clusters, and in the third period there was a differentiation of yield growth rates. It is the largest in the forest-steppe zone, the smallest in Polissia, and in the transition zone, the growth rate has an intermediate value.